1. Field of the invention
The invention concerns processing means for cutting free the fillets from the belly radii, these means comprising a pair of knives arranged essentially parallel to each other, a guiding device which is positioned in the region of the knives, supports the flanks of the fish and guiding elements which can be pushed apart synchronously in a counter-direction to each other by the fish to be processed, as well as a conveyor for moving the fish along the processing tools.
2. Description of Prior art
In the mechanical production of fillets from slaughtered fish, i.e. fish opened at their belly and gutted, it is important to carry out the corresponding working processes as economically as possible and to ensure a high product quality as well. In order to meet these requirements it is necesary to make the course of processing so precise that the necessity of additional trimming work, i.e. of manual correction to the fillets produced is at least greatly reduced and preferably becomes superfluous, and that the processing can be carried out with the least possible loss of yield.
Because it is forbidden to land cod-like fish such as cod, haddock, shellfish, etc. unslaughtered the fish are slaughtered on board directly after the catch. The belly cut for opening the belly cavity is carried out so that the abdominal cavity bag which, in fish of this kind, recedes back beyond the anus into the tail part is also opened so that the entrails can be removed more safely. For this purpose the belly opening cut is ended behind the anus in the region of the ventral fin directly behind the anus, the cut running, unsymmetrically, at least in the area of the ventral fin, i.e. close to, but laterally spaced from the same.
When fish prepared in such a manner are filletted it has been noted that the ventral fin usually remains on the fillet so that additional trimming work is necessary. This is because usually the guiding of the fish during the processing occurs by rigid guiding elements arranged in pairs and symmetrically to the path of the fish and formed mirror-inverted, which elements are each held resiliently under counter-directed synchronisation against the flanks of the fish (see e.g. French Patent No. 999 714). In such a handling the part of the fillet connected to the ventral fin, which part was already set loose by the belly opening cut, runs, due to its varying consistency, size, thickness and deformation through storage, through the machine along an undefined path so that a calculated and well defined separating of the ventral fin is not possible. In addition to the necessity of inspecting resp. trimming the fillets this uncertainty also leads to the inclusion of a skinning process into the mechanical processing course not being satisfactorily solvable since the ventral fin attached to fillet can effect a disturbance of the skinning process which becomes apparent in the form of skinning mistakes on the relevant fillet and in the impossibility of maintaining a continuous passage.
3. Objects of the Invention
It is therefore an essential object of the invention to ensure that fillets gained by using filletting machines are fin-free.
It is another object of the invention to achieve such fin-free fillets with the minimum possible loss of yield.